Princo Instruments Inc. of Southampton, Pa., introduces its latest High-Perform-X™ Null-Kote™ detectors for obstructionless presence/absence detection of liquids and solids in all types of process lines and piping. The Model L3515 is comprised of an electronics unit housed in a heavy-duty, cast aluminum, explosion-proof enclosure and an integrally mounted sensor available in a variety of flange types. The unit includes a relay with dual 10A 115Vac (resistive) control contacts.